This invention relates to range hoods for use in domestic kitchens, and more particularly to a motor housing and single fan assembly for use in a range hood for drawing grease laden air from above a cooking surface and venting to an external location.
Range hoods are used above cooking surfaces to remove grease, common odors and hazardous gases created during the cooking process. The range hood has an outer hood body having top, bottom and side panels defining an enclosure. A motor housing having top, bottom and side surfaces defining a further enclosure is contained within the outer body.
There are two basic designs for range hoods for domestic usexe2x80x94a single motor design and a double motor design. An example of the single motor design is shown in U.S. Pat. No. 4,500,331. The ""331 patent teaches a motor housing having top and bottom surfaces, a curved outer wall and an extended end portion. There is an air inlet in the bottom surface and an air outlet in the top surface in the area of the extended end portion. An electric motor is mounted to the top of the housing and a centrifugal fan attached to it. The motor and fan are positioned above the air inlet. The space between the outer circumference of the fan and the curved outer wall of the housing increases in the direction of rotation of the fan, the space being the largest in the area of the extended end portion, thereby maximizing air flow. In order to maximize the size of the motor and fan employed, the extended end portion and the outlet vent located there are positioned off center within the range hood body (the range hood being larger from side to side than from front to back).
For individuals making greater use of grease when cooking, a more powerful range hood, such as the double motor design, is needed for proper removal of the grease fumes generated. In the double motor design, the motor housing has top, bottom and perimeter side surfaces defining an enclosure having two substantially mirror chambers, each with an air inlet at the bottom and an air outlet at the top. A motor and fan is positioned in each chamber above the air inlet. The fans suck air from the cooking area below and force it through the motor housing chambers to the air outlet where it is directed by ventilation piping to the outside. The space between the outer circumference of the fan and the perimeter side surface of the respective chamber of the housing increases in the direction of rotation of the fan, the space being the largest in the area of the air outlet. By having two motors and fans, greater suction power is provided. In addition, the air outlet may be centered between the sides of the range hood.
While more powerful, the double motor design range hood is more costly to produce. In addition to requiring two motors and fans and the additional wiring and electronics associated with this, the motor housing itself is larger requiring greater material for production.
Accordingly, it is an object of an embodiment of the invention to provide a range hood having a single motor and fan that is more powerful than the single motor and fan design of similar sized range hoods of the prior art.
Not all aspects of the invention necessarily address such object. Other objects of the invention will be apparent from the description that follows.
According to the preferred embodiment of the present invention there is provided a range hood motor housing and fan assembly. The assembly comprises a motor housing having top, bottom and side surfaces defining a chamber that is mounted within a range hood body. A motor is housed within the motor housing chamber, the motor including a fan having a plurality of fan blades. The fan is adapted to rotate about the motor. An air outlet is located in the motor housing. Space between the fan blades and the top surface of the motor housing increases in the direction of rotation of the fan from one side of the air outlet to the opposite side of the air outlet.
In another aspect, the motor housing further comprises an upper section and a lower section, the sections being releasably connectable to one another.
In yet a further aspect, the lower surface of the motor housing has a wall projecting into the chamber defining an air inlet. The air outlet is located in the top surface of the motor housing.
In yet a further aspect, the fan comprises a plurality of arcuate fan blades having front and rear faces, a basket housing, and an outer cylindrical stabilizing element. The fan blades project radially from the basket housing to the outer cylindrical stabilizing element. The fan blades may have at least one trough on their respective front faces. The troughs decline at an angle from the basket to the stabilizing element.
In yet a further aspect the side surface is substantially cylindrical and is substantially concentric to the stabilizing element.
In an alternative embodiment of the assembly described above, a portion of the top surface and of the air outlet overlaps the bottom surface.
According to the present invention there is provided a fan for use within a range hood for exhausting gases generated above a cooking surface comprising a plurality of arcuate fan blades having front and rear faces, a basket housing and an outer cylindrical stabilizing element. The fan blades project radially from the basket housing to the outer cylindrical stabilizing element.
According to an alternative embodiment of the present invention, there is provided a motor housing and fan assembly as detailed above that further comprises an air exhaust chamber. The air exhaust chamber has an inlet portion, an intermediate portion and an outlet portion. The inlet portion connects to the motor housing. The outlet portion connects to an opening in the hood body. Air from the motor housing passes through an opening into the inlet portion, through the intermediate portion and then is vented through venting slits in the outlet portion through the opening in the hood body to the range hood exterior.
The foregoing was intended as a broad summary only and of only some of the aspects of the invention. It was not intended to define the limits or requirements of the invention. Other aspects of the invention will be appreciated by reference to the detailed description of the preferred embodiment and to the claims.